DROSOPHILA PATTERNS FOR TWO PTERIN COFACTOR DEFECTS

两种蝶呤辅助因子缺陷的果蝇模式

• 批准号: 6592825
• 负责人: JANN P PRIMUS
• 金额: $ 8.4万
• 依托单位: SPELMAN COLLEGE
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-02-01 至 2003-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6592825
• 关键词: Drosophilidae; aldehyde /ketone oxidoreductase; aldehyde reductase; cofactor; cytogenetics; enzyme biosynthesis; enzyme complex; enzyme substrate; gene mutation; high performance liquid chromatography; in situ hybridization; inborn metabolism disorder; laboratory rat; molecular cloning; nucleic acid sequence; protein purification; pteridines; radionuclides; tetrahydrobiopterin

In born errors in the biosynthesis of the pterin cofactors tetrahydrobiopterin (H4B) and molybdopterin (MoCo) are associated with serious human diseases. Genetic variations in the synthesis of H4B have been associated with serious human diseases. Genetic variations in the synthesis of H4B have been associated with diseases such as atypical phenylketonuria, Parkinson's disease, and dystonias. The importance of H4B to these processes is found in its role as an essential cofactor for phenylalanine, tyrosine and tryptophan hydroxylases, enzymes that are involved in amino acid degradation and the biosynthesis of catecholamines and serotonin. The MoCo functions as an essential enzymatic cofactor for molybdenum hydroxylase enzymes such as sulfite oxidase and xanthine dehydrogenase. Genetic deficiencies in the biosynthesis of the MoCo ar3e associated with a severely debilitating neurological disorder, molybdenum cofactor deficiency, and with xanthinuria, a malady of purine metabolism. The proposed studies utilize Drosophila melanogaster, the only model system in which changes in pterin synthesis are reflected in a visible phenotype (eye color), as a genetic model system for pterin cofactor biosynthesis. The studies center on two Drosophila proteins, aldose reductase and the maroon-like+ (ma- 1+) protein, which are involved, respectively, in the synthesis of H4B and MoCo. Expressed sequence tags (ESTSs) identified from partial amino acid analysis will be used to obtain molecular clones encoding the aldose reductase. Aldose reductase clones will be used as probes to determine the cytogenetic locus of the aldose reductase gene(s). Knowledge of the cytogenetic locus of the aldose reductase will allow mutant analysis to assess the protein's involvement in the H4B pathway. Polyclonal antisera raised to maroon-like (ma-1) peptides will be used to follow the standard purification of the maroon-like protein, a putative cysteine transulfurase, and the first eukaryotic member of the nif-S-like gene family to be described. Such antibodies will also be used to localized the ma-1 protein in situ and to analyze existing ma-1 mutants. These studies will lead to a better understanding of the terminal steps of BH4 and MoCo biosynthesis in higher organisms.

在蝶呤辅助因子生物合成的先天错误中，四氢生物蝶呤(H4B)和钼多蝶呤(MoCo)与严重的人类疾病有关。H4B合成的遗传变异与严重的人类疾病有关。H4B合成的遗传变异与非典型苯丙酮尿症、帕金森病和肌张力障碍等疾病有关。H4B在这些过程中的重要性在于它是苯丙氨酸、酪氨酸和色氨酸羟基酶的重要辅因子，这些酶参与氨基酸降解以及儿茶酚胺和5-羟色胺的生物合成。MoCo是钼羟基酶如亚硫酸盐氧化酶和黄嘌呤脱氢酶所必需的辅酶因子。MoCo生物合成的遗传缺陷与一种严重衰弱的神经疾病，钼辅助因子缺乏，以及黄尿症，一种嘌呤代谢疾病有关。所提出的研究利用黑腹果蝇作为蝶呤辅因子生物合成的遗传模型系统，这是唯一一个以可见的表型(眼睛颜色)反映蝶呤合成变化的模型系统。这些研究集中在果蝇的两种蛋白质，即醛糖还原酶和栗样+(ma-1+)蛋白，它们分别参与H4B和MoCo的合成。从部分氨基酸分析中鉴定出的表达序列标签(ESTs)将被用于获得编码醛糖还原酶的分子克隆。将利用醛糖还原酶克隆作为探针，确定醛糖还原酶基因(S)的细胞遗传学基因座。了解醛糖还原酶的细胞遗传学位置将使突变分析能够评估该蛋白质参与H4B途径。多克隆抗血清被提升为栗样肽(ma-1)，将用于标准纯化栗样蛋白，推测是半胱氨酸转移硫酶，也是第一个被描述的NIF-S样基因家族的真核成员。这种抗体还将用于原位定位ma-1蛋白并分析现有的ma-1突变体。这些研究将有助于更好地理解高等生物中BH4和MoCo生物合成的末端步骤。